This invention relates to circuit breaker housings and more particularly relates to a novel circuit breaker housing which is segmented, with each segment carrying a respective bushing which can be fixed in any desired adjustable angular relationship with respect to the other bushing.
Circuit breakers of the same rating are used in both metal-clad switchgear installations or in outdoor substations as free-standing circuit breakers. Thus, a circuit breaker having a 15 kV nominal service voltage can use a given basic interrupter structure and operating mechanism but requires many different interrupter housing parts, depending on whether it is for metal-clad switchgear or for an outdoor free-standing circuit breaker application.
For example, in a metal-clad draw-out switchgear application of well-known variety, the pole spacing for a 15 kV nominal service voltage would be about 10 inches center to center between the parallel axes of the bushings of adjacent poles of the circuit breaker. This spacing is adequate to provide space for current transformers and for insulated plug-in entrance bushings of conventional type. The vertical spacing between the bushings of each pole can be of the order of 12 inches, although this is determined by the interrupter size. For an outdoor free-standing circuit breaker application, however, where insulated plug-in bushings are not employed, it is necessary to provide a relatively large air-insulated line-of-sight gap between the terminals at the free ends of the bushings. This requires a spacing, bushing to bushing, greater than about 15 inches both vertically and horizontally.
Because of these different requirements for bushing separation, for metal-clad switchgear application or free-standing outdoor application, the following complexities arise:
(a) The different circuit breakers must employ different single-pole housing sizes.
(b) The different circuit breakers must employ different manifold lengths.
(c) The circuit breakers employ jackshafts from the operating mechanisms of different lengths.
(d) The two different breaker forms have different gas volumes wherein the gas volume for the outdoor breaker is larger than for the metal-clad switchgear.
A principal object of this invention is to effect substantial economy in manufacturing and inventory costs, by providing an arrangement for a circuit breaker housing in which the same basic interrupter housing section is used for either a metal-clad application or a free-standing substation application.